Looking for information on magnetic decouplers (both permanent and electro). I would appreciate reading any recommendations and experience with selection, installation, and operation.
Thanks in advance.
I have a number of each of the Kadee varieties - above the ties, below the ties and electromagnetic.
The above the ties models are the simplest. However, I found that they didn’t sit between the tie plates on Atlas code 100 track like they should, so I had to do some trimming. Also, the recommended height, slightly above the railheads, caused one of my locomotives to run aground. I lowered the magnet and it still uncouples fine.
For more recent installations, I used the beneath the tracks model. These are much stronger magnets. They may actually be too strong, as they draw the metal axles and wheels towards their center, sometimes complicating the uncoupling process. They come with an “intensifier plate” which I would leave out next time.
The electromagnets work fine, too. I have them on my mainlines, where I don’t normally want uncoupling to take place. Like the under-the-track permanent magnets, you need to plan where they go, but even more so since you’ll need to cut a relatively large hole to accomodate the coil. The electromagnets require a large power supply, 16 volts at 3 amps, as I recall. Kadee offers such a supply, but if you take the manufacturer and model number from the one they’ve got, you’ll find the same supply at Mouser for a lot less money. The electromagnet wants DC, and that supply is AC, but the magnet unit comes with a heavy-duty diode bridge to do the conversion. Remember to pick up some heavier wire, too, at least 18 AWG for this.
General rules: Don’t even think of putting them on a curve. You will want to put them on a straight section, long enough so that you’ve got a full car length of straight track on either side of the magnet. This keeps the couplers aligned straight and allows easy uncoupling. Also, get a Kadee coupler gauge, and make sure all your couplers are the right height and have properly-adusted trip pins. (I’ve got the Kadee trip-pin plier
Sly cunning trick for an inexpensive, no false uncoupling variant to the under-tie permanent magnet. Mount it on something like a long-armed rustic hinge, artistically bent so the magnet drops down for normal operation. Pulling the operating cable raises the magnet up against the underside of the one layer of card stock covering the hole in the roadbed, thereby allowing controlled uncoupling. The operating cable is a length of monofilament fishing line, guided by small screw-eyes, with a big bead at the aisleway directly in line with the uncoupling ramp. No need for a big electromagnet or a non-standard dedicated power supply.
Both legs of the hinge are bent into L shapes, and the hinge pivot is close to the top of the roadbed - just deep enough to allow the magnet to make flat contact with the card stock. The fixed leg of the hinge is screwed upward into my plywood subgrade. I’m using a Microtrains #308 N-scale magnet, which works fine with my HO Kadees mounted on 1:80 scale rolling stock. It would probably stay stuck to the hinge with magnetism alone, but I added a bit of superglue just to make sure.
Much of my rolling stock is fabricated of real tinplate (galvanized steel sheet) so a fixed, powerful magnet would uncouple almost every car. My depressed center flat car has actually lifted poorly-affixed above-the-ties magnets and carried them off.
Chuck (Modeling Central Japan in September, 1964 - with drop-mounted track magnets)
Chuck,
Your uncoupler idea sounds pretty cool. Do you happen to have any pics or drawings of it?
Thanks,
-Ed
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I have attached my top of ties type with Walthers Goo, so I can move them as I learn more how operations will go.
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There is a larger under track(inside roadbed) magnet that works pretty well. It’s pretty easy and well hidden as you just cut out some of the roadbed directly under the ties. It comes with a figure which helps identify where it’s placed–I think it’s a Bachmann, not sure though.
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If you have a hidden magnet it really helps to mark where it is with something like a mile marker, etc.
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It has been mentioned to make sure you’re on tangent track for at least 2 car lengths. To me, you may want more. Also, be careful to consider the grade. Hard to uncouple if the train is stretched out or pushed together. I also have small chock blocks that help sometimes.
Richard
You might want to consider using the “Totally Hidden Uncoupler” made by S & L Enterprises in Sykesville, MD. I ordered one recently from MB Klein to try. They’re made in HO and N scale versions. The unit consists of a steel plate on which 4 rare earth disc magnets are arranged. For N scale, the plate is 1/16" thick by 5/8" wide by 7/8" long. The rare earth magnets are 1/16" thick and 3/16" diameter. If you’re using cork roadbed under your track, you can cut out a section of the cork roadbed and the unit will slide under the track. I’ve played with the unit I bought. It seems to uncouple fairly reliably, but it does take some fine tuning of the positions of the magnets on the steel plate. Once you have the magnets in their final position, you can glue them down with super glue, etc. I would not use these units on your Mainline.
There was a review on these uncoupler units by Phil Scandura in the September 2007 issue of Model Railroad News. I think I found the article through a Google search.
Bob
I use 1" ceramic permanent magnets on my HO Layout. You can buy these at Radioshack. You get five magnets for about $3. But you have to use two magnets together side by side. I lay them under and touching the ties. You can then ballast the track and never know there are there. I use scenery elements such as shrubs or pile of rock etc. to identify where they are.
Before you balast the track be sure and run cars over them and do some uncoupling. You can even use these on curves but the magnest will have to be positioned off center.
The November 2008 MR had an article about using small disc or pin type Neodymium magnets for uncoupling. A pair of small thin disc type magnets can be slipped under rails, one under each rail between a pair of ties, or small 1/8" X 1/2" or 3/8" pin type magnets can be glued in small holes set just inside the rails between ties. The heads of these magnets need to be something between .020’-.030" below the railhead, and just far enough from the insides of the rails to clear wheel flanges. The author mentioned using a 4 penny finishing nail with it’s head cut off as a spacer. He also recommends marking the magnet locations.
I’ve used the 1/8x3/8s before. N42 grade I think, from K&J. They’re dirt cheap. They’re reliable and practically invisible.
One thing I loved about them is you can customize the size of the magnet array for sure-spots. I had a test spur with one magnet on each rail. You had to spot the car PERFECTLY to get the decouple. A more reliable array was four on each side.
And to make them attractive to me, besides CHEEP is the apparent ease of installation. Just a 1/8" drill, a cheap spacer, and maybe a jig out of scrap material to adjust the height.
FYI: This method using Radio Shack Ceramic Magnets was mentioned in a letter by Chris Kieffer to the “Safety Valve” column in the February 2009 issue of Railroad Model Craftsman on page 6. The Radio Shack part number is 64-1879. I tried using these magnets for uncoupling on my N scale track and found them not to be very effective. Plus they are wider than N scale track and would be difficult to hide with ballast. Maybe they work fine in HO.
Bob
With regard to the referenced November 2008 article on the use of rare earth magnets, this article actually appeared in the November 2008 issue of Railroad Model Craftsman on page 83, not in MR as originally referenced
Bob.
You’re Right. My bad. My computer screen mislead me. It was the November 2008 RMC. Not sure if I need new glasses, or new eyeballs.